I'm experiencing a problem with the climate control system in my 89' convertible. I am unable to change the vent settings or even turn the AC/heat off. At present the light indicator above the defrost setting is illuminated, but when I go to change to bi-level, or another setting I push the button and no response, the system continues to blow through the defrost. Also there is no response from the on/off button. I have searched the old posts in this forum but have been unable to find anything similar, if I did overlook a previous post that discusses this problem I apologize. Does anyone have any suggestions or has anyone experienced a simillar problem? Initilly I'm thinking it's the climate control unit itself. Any help with this situation is geatly appreciated.

 

If the 89 is like my 94 (and I think it's pretty similar), you can remove the climate control unit from the dash and take it apart to clean the button contacts. I did it on mine with stellar results. If you decide to do it just remove it carefully from the dash being sure to note where the screws and plug ins go etc. Then there will be five screws holding the front section of the unit to the box in which the electronics are contained. One of the screws actually holds the circuit board in place inside (if I remember correctly). Be very careful disconnecting the flat cable from the front section inside and just note how everything is situated as you take it apart so it will be more obvious how it goes when you put it back together. Once you have the front section removed you will see that you've unplugged a circuit board behind the face which has the LCD readout panel on it and this circuit board is actually where one half of each of those buttons are mounted. Before you take the circuit board out of the front section lay it down on a table face down. If you just pull it out all the buttons will fall out and you will be hard pressed to remember where they went and you're in for a frustrating time. The thing is, the circuit board has all of the electrical contacts and necessary wiring integrated into it to make everything work. The buttons just have contacts on them and when you press one you are simply completing the circuit for that function by connecting the "wires" (they're not actually wires, they're like little strips of tin foil routed on the board) to each other. Now, these connections between the back of the buttons and the little patches of circuitry on the board get dirty, and that's when the button stops working. Use some alcohol and Q-tips to clean all of these little patches on the board and the contacts on the back of the buttons, carefully put it all back the way it came (be very careful plugging the flat cable back in) and reinstall it in the car. At this point, all the buttons should work like new!

If it doesn't the problem could be elsewhere or maybe you missed something. At any rate, it doesn't work now so you don't have much to lose. I have seen these units for sale on Ebay but dirty contacts are the problem with that kind of device (including TV remotes, or anything that has push buttons these days) almost 100% of the time.

I hope I didn't sound condescending in my explanation, I just don't know how much you know about electronics etc. so it's usually best to explain in as simple and complete terms as possible. Not that I know all that much but I've done that type of thing successfully a few times and I just happened to do exactly the same job just the other night on mine.

Hope it works out! I know how frustrating it can be when that silly climate control thingy doesn't work right. If you have any more questions about it let me know. I wish I would have thought to take pictures of the process the other night so I could've posted them.

Rod

 

Rod I appreciate the input. Cleaned the contacts throuoghly last night to no avail. I am going to order the AC/heater control unit and see if that doesn't correct the problem. In case anyone wants to know the removal was fairly easy, once the console bezel, and center dash bezl are removed there are only four screws that hold the unit to the dash. Once the screws are out there is a single plug in harness in the back and once its removed the unit is out. The unit itself has an interesting design. There are 3 pieces to the control unit - 1. a black plastic housing 2. sitting inside the housing is basically a circuit card, and 3. onto the front of the circuit card is the face plate with all the buttons. There are 2 small metal retaining clip, one on either side of the control unit, I used a pair of needle nose pliers and removed them and the unit comes apart into the seperate pieces. I'll post back once the control unit comes in and see if that doesn't fix the problem. Thanks for the help.